Malicious Code Detected in pywin-simple-gui: A Threat to Users
Summary
MAL-2026-933: Malicious code in pywin-simple-gui (PyPI). Affects pywin-simple-gui versions 1.0.0. No fix is published. How to fix ↓
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Background
pywin-simple-gui is a Python package available on PyPI, designed to assist developers with GUI applications on Windows. It offers a simplified interface for creating graphical user interfaces. However, this package has been compromised, leading to serious security concerns for users who may unknowingly install it.
Vulnerability Detail
The vulnerability originates from a malicious campaign identified in February 2026, where the package masquerades as a development helper but actually downloads and executes a remote executable. This executable can disable Windows Defender, indicating a high level of malicious intent, including potential cryptocurrency mining activities and communication with a command-and-control server via Telegram.
How To Fix
This package is malicious. Remove it and rotate any credentials it could have accessed.
pip uninstall pywin-simple-guiIf it arrived as a transitive dependency, remove the package that pulled it in, then reinstall.
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Workaround
As a temporary measure, users can avoid using pywin-simple-gui until a secure version is released. Additionally, consider using alternative packages for GUI development that have a proven track record of security.
Conclusion
The pywin-simple-gui package has been identified as malicious, posing significant risks to users. It is crucial to uninstall the affected version and monitor for updates or patches. Utilizing tools like Vulert can help in maintaining the security of your software dependencies.
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FAQ
pywin-simple-gui is a Python package designed to simplify the creation of graphical user interfaces on Windows.
If you have installed pywin-simple-gui version 1.0.0, your system may be at risk. Check for any unusual activity or files.
Uninstall the package immediately using 'pip uninstall pywin-simple-gui' and monitor your system for any suspicious behavior.
Yes, you can use Vulert, which monitors and alerts for open-source vulnerabilities in your software without requiring code access. Visit https://vulert.com for more information.
Yes, you can use the Vulert playground at Vulert Scanner to check for vulnerabilities in your application without any signup.
